【作者】 窦伟坦；

【导师】 田景春；

【作者基本信息】 成都理工大学 ， 古生物学与地层学， 2005， 博士

【摘要】 本文以鄂尔多斯盆地三叠系延长组为研究对象,运用沉积学、层序地层学、石油地质学、地球物理学等理论,以大量的野外地质资料为基础,综合了大量钻井和测井资料,采取多方面相互补充,完善,理论研究与实际研究相结合,宏观研究与微观研究相结合的方法,系统分析了鄂尔多斯盆地的沉积体系类型及特征;深入、详细、系统研究了主力油层的沉储层特征及控制因素;重点讨论了油藏形成条件及其控制因素,建立了油藏形成模式。取得的主要成果和认识概括为以下几方面: 1、在详细研究沉积体系确定标志的基础上,首次从全盆角度研究出发,将鄂尔多斯盆地上三叠统延长组划分出东北、西南两大沉积体系,分别由冲积扇、河流、扇三角洲、辫状河三角洲、曲流河三角洲、湖泊等组成。详细论述了各沉积体系的特征,指出扇三角洲、辫状河三角洲和浊积扇主要分布于盆地的西缘;曲流河三角洲主要发育于盆地北部、东部及东南部地区。分别建立了各沉积体系的沉积模式。 2、在此基础上系统论述了全盆地延长组各油层组沉积体系时空演化和展布特征。沉积体系平面展布特征控制砂体展布。西南沉积体系的砂体形态为条带状,呈东西向、北东向、南北向展布,砂岩的成分成熟度和结构成熟度较低;东北沉积体系砂体连片性好,以席状、朵状为主,呈北东向展布。纵向上从长8—长2总体呈现向南进积的趋势。 3、砂岩储层的孔隙类型以粒间孔、长石溶孔、岩屑溶孔、浊沸石更多还原

【Abstract】 This paper investigates the Yanchang formation in Triassic system of Ordos basin, using theories as sedimentology, petroleum geology, geophysics, et al. based on abundant outcrop sections, well drilling and seismic data. This paper synthesis a lot of welling and petroleum geology. This paper also systemic analyse the characteristics of deposition systems in Ordos basin and sequence stratigraphic, go down to research sedimentary microfacies of the leading pay formations, sand bodies and its distributions, reservoir characteristics and control factor, adopting the technique methods of academic research combined with practice research and macroexaminations combined with microexaminations. This paper detailed discuss the formation condition and controlling factor of reservoir, building the model of forming reservoir. This paper take out main results and realizations as follows:1. Through detailed research the identification of Sediment System ,The deposition systems of the Yanchang formation in Triassic system of Ordos basin compose of alluvial fan, fluvial deposition, fan delta, braid delta, meandering river delta, lake. This paper detailed discuss every the characteristics of deposition systems, alluvial fan, braid delta, turbidite fan mainly lies in the west of basin, and meandering river delta mainly development the north, east and southeast of basin, sedimentary models are founded.2. On the basis of systemic discuss the characteristics of every oil layer’s deposit facies zone and the distributions of sand body. The distributions of the sand bodies are controlled by deposition system. The distributions of the sand bodies are controlled by deposition system. Southeast deposition system’s sand bodies’ configuration that have low component and textural maturity presents a band shape of east-west and northeast-southwest trend from Huanxian to Zhengning. Northeast deposition system’s sand bodies which have a good continuity presents a northeast-southwest trend in the plane and a general trendof progradation to the south in the cross section in the strata from member 8 to member 2 of Yanchang formation.3. The interstices in the majority reservoir sand includes intergranular porosity, feldspar interstice, lithic fragment solution hole, laumonite solution hole(which does not appear in braid river delta in the southwest) and intercrystal porosity that is the main accumulating space. Sedimentary enviroment is the main geological basis which affects the reservior’s storability by analyzing the contribution factor of reservoir, Mineral component and grain size of the sandstone are important conditions which affect the reservior’s storability. Component, content, and diagenesis of the matrix are the dominant factors which affect the reservior’s storability. Microfissuring can greatly reform the reservoir permeability.4. The formation mechanics of petroleum deposit in the Yanchang formation in Triassic system of Ordos basin is gone deep into analyse. The type of petroleum deposit is the rock character petroleum deposit that mainly controlled by deposition system. According to the formation controlling factor of petroleum deposit, the Yanchang formation in Triassic system of Ordos basin is further divided into consists four species, i.e. lithologic oil pool, structural lithologic reservoirs, stratum lithologic reservoirs, contrast erosion petroleum deposit. Petroleum deposit found in ch3’s oil layer and upper stratum usually belongs to structural lithologic reservoirs, its struture formation is bound up with compaction of action. Petroleum deposit found in ch6-8 oil layer mainly belong to lithologic oil pool, a few rate of structural lithologic reservoirs, principally distribute the west of fault brand area and the south of Weibei area.5. Analysed the controlling factor of petroleum deposit are pointed to: the distribution of petroleum deposit(especially ch6-8 petroleum deposit)is clearly controlled by the thickness of oil source rock, the intensity of generation hydrocarbon, the intensity of expulsion hydrocarbon. Ch7 is the main oil source rock in the basin. Its character is that Have the thickness big, distribut range wide, organic quality plentifulness, organic type kind, maturity high. The upper of ch7’s oil source rock is ch6’s standrock of Northeast delta, covered the lower side of ch7’s oil source rock that southwest braid of ch8’s sand rock belong to the beneficial layer that is in favor of accumulating oil and gas. The advantage sedimentation facies zone is the basic geology condition of delta oil pool, the更多还原